Most of us probably thought the Casio F-91W was just another cheap and crappy plastic watch—that is, if we thought about it at all. Turns out the 20-year-old design has found a loyal fan base not just among nostalgic nerds but also with bomb-makers, to the point where merely owning one makes you a candidate for Guantánamo Bay. It's a strange world out there. Moral of the story: stick to analog watches.